Fluid filled high tension terminal



Inventor: Eugene D. Ebg,

Wk Hus Attorneg.

July 25, 1933. E. D. EBY

FLUID FILLED HIGH TENSION TERMINAL Patented July 25, 1933 UNITED STATESPATENT OFFICE EUGENE EBY, OF PITTSFIEIID, MASSACHUSETTS, ASSIGNOR TOGENERAL ELECTRIC COMPANY A. CORPORATION OF NEW YORK' FLUID FILLED HIGHTENSION TERMINAL Application filed April 27, 1932. Serial .No. 607,748.

The present invention relates to terminals for high tension electriccurrents and especially to terminals for use with high tension cableshaving a channel filled with fluid insulation.

Briefly stated suchterminals comprlse a metal base portion or memberwhich 1s sealed to the sheath of the conductor, a

1 relatively tall chambered insulator, com

monly made of porcelain, into which the conductor extends, a metal capfor the porcelain, a means'extending through the cap by which current isconveyed from or to the conductor, and a fluid filling for the chamberof the insulator and cable.

A terminal to fulfill all of the exacting service requirements shouldhave means to compensate for plus and minusv variations in the height ofthe porcelain insulator; means to compensate for the expansion andcontraction of the conductor; means to control the fluid within thecable or conductor during assembly of the parts; means to free theconductor core and terminal parts of foreign matter, a fluid controllingvalve and means accessible from a region outside of the terminal to lockthe valve in its open position after the parts are assembled and readyfor normal operation, which means also permits of subsequently openingthe valve should occasion therefor'arise.

The object of my invention is the provision of'a terminal of improvedconstruction which will fulfill all of the exacting requirements abovespecified, and which is also of simple and rugged construction.

For a consideration of what I believe t be novel and my invention,attention is directed to the accompanying description and the claimsappended thereto.

In the drawing which is illustrative of my invention, Fig. 1 is a viewin elevation of a terminal ;.Fig. 2 is an enlarged sectional view of apart of the terminal; Fig.3 is a detail illustrating the fluidcontrolling valve, and Fig. 4: is a sectional View taken in line 44 ofFig. 2.

5 indicates a metal base having a flange or other means whereby it maybe supported in a vertical position. To the lower end of the base issecured a fluid containing metal sheathed cable 6, as by a wipedsoldered joint 7 for example. Supported by the base is a porcelain orequivalent insulator 8 having numerous projections or ribs 9 to increasethe creepage surface forelectric currents. The insulator is relativelytall, of relatively small diameter and has a central chamber 10containing fluid insulation, such as thin degasified oil for example.Located within the chamber are one or more cyline drical barriers 10*.Such insulators are liable to vary considerably in length duetoshrinkage in the firing I operation. The lower end is' seated on themetal base and secured thereto by a fluid tight joint in the usual way.Seated on the top of the insulator is a metal cap comprising a memberhaving a horizontal flange 11 and a depend ing or inset portion 12 ofconsiderable length having a central opening of hexagonal or othershape, other than round, as shown in Fig. 4, to prevent relative turningof it and the terminal parts extending therethrough. By making the inset12 of considerable depth, it will permit of considerable variation inthe height of the insulator while'preserving the desired relation withthe conductor parts. Surrounding the upper end of the insulator andsecured thereto by cement cap member is secured by numerous bolts.

Between the cap and the top of the insulator is a flat tion.

llhe means for transmitting current from the cable to the outside of theinsulator comprise two members, one being supported directly by theconductor and indirectly by the base, the other being supported by themetal cap. Extending through the central opening in the cap member is astud or ter minal member 14, the lower end of which is shaped to preventit from turning Within the opening in the inset as shown in Fig. 4:. Theupper end of the stud is externally screw threaded and mounted thereonis a nut 15, the latter being seated on a shoulder on'the gasket to makea fluid tight conneccap member. Enclosing the upper end or" the stud isan internally screw threaded hollow terminal holder 16 having a flangeat its lower end resting onthe nut v15. The terminal holder is securedin place by a clamping ring 17 and numerous bolts. Between the meetingsurfaces is a gasket to ensure a fluid tight joint.

18 indicates the insulation on the stranded conductor 19, and 20 handwrapped insulation such as varnished cambric applied after the terminalparts are assembled on the conductor. The conductor is hollow and in theupper end thereof is located a tube 21 for supporting the strands of theconductor and forming a-continuation of the conductor core. 22 indicatesa lower terminal member or holder having a socket 23 in its lower' endto receive the strands of the conductor, there being small holes 24 inthe wall of the socket through which string solder is fed to unite theparts. The holder is provided with a valve seat 25 opening into the coreof the cable. Above this are one or more lateral ports 26 to permitfluid to flow betweenthe core of thecable and the chamber 10 of theinsulator. In addition to being soldered to the tube the hold or is alsosecured thereto by set screws 27. The upperend ofthe member'has atubular extension 28 acting as a spacer to hold the flexible connectors,to be referred to later, away from the central parts. The member is alsoscrew threaded and mounted in the threaded part is a guide tube 29; thelatter extends into the hollow terminal member above and is internallythreaded for a short portion of its length to receive the threaded partof the valve 30, and also is provided with lateral ports 33 to permitthe passage of fluid.

From the structure thus far described, it will be seen that the cableand its terminal parts are supported by the metal base 5 and that thestud 14 and associated parts are supported by the cap of the insulator.To compensate for unequal expansion and contraction of the various partsas they heat and coolin service, the upper and lower terminal membersare electrically united by numerous flexible connectors 34:, the latterbeing made of braided wire having end caps which are pinned and solderedto the terminal parts.

In addition to compensating for expansion and contraction in an axialdirection,-

the'flexible connectors also permit of a limited misalignment of theupper and lower terminal members whichis advantageous as it avoidsobjectionable strains on any of the parts. In other words, no harm willresult ifflthe metal cap is not exactly parallel with the base, as itshould be. In this connection,

it will be noted that there is considerable.

lateral clearance between the various tubular elements located in orforming parts of the upper half of the terminal.

The valve 30 has a long tubular stem 35, the upper end of which isslotted as indicated at 36. In order to rotate the valve both to seatand unseat it, a small rod 37 is provided which has a pin 38 enteringthe slot. The upper end of the rod is secured to a short screw or plug39 located at the top of the terminal. The screw, rod 3:? and pin 38serve as a wrench to open and close the valve and form a permanent partof the terminal. During assembly of the terminal, the valveis closed toprevent escape of fluid from the cable and for normal operation is wideopen. Prior to assembling the part 16 in place the valve may be removedand a rod or other implement inserted in the tube to ensure that thevalve seat and core of the conductor are free of foreign matter.Assuming that the valve is closed and that it is desired to open it, thescrew 39, rod 37 and pin 38 are used as a'wrench, as indicated in Fig. 3and the valve is moved upward to the position shown where it is eitherout of engagement with the screw threads in the tube 29 or at least onlyone or two threads are engaged To seat the screw 39 without closing thevalve, said screw is moved axially into engagement with the threads. inthe end of the part 16, the pin and slot or slip connection between therod and tube 35 permitting of this. As

soon as the threads engage, the valve will rotate with the screw 39, butsince the valve is separated from its seat by a distance substantiallygreater. than the length of the threaded part of the screw, the efiectwill be to move the valve downward by an amount determined by the lengthof the thread on the screw, but not enough to either close the ports 26or the valve seat or opening 25 in the lower terminal member. Ow-

ing to the pin and slot connection, unequal expansion of the variousparts of the terminal cannot cause any binding or injurious action onthe valve or its actuator. Once the screw is seated it holdsthe valvelocked against further movement.

The upper end of the part 16 of the upper termmal member is externallythreaded to receive the nuts 40 by means of which a conductor meansleading to or from an electrical apparatus may be secured.

Due to the hexagonal surfaces on the upper terminal member 14 and to thecampanion surfaces or wall defining the bore'in the bottom of the inset12, as shown in Fig. 4, the member 14 is prevented from turning when awrench is applied to tighten the 1 part 16 thereon. Preventing relativeturning of these parts also prevents torsional strains from beingtransmitted to the flexible connectors which being of rather lightmaterial might be injured thereby.

- and supported by the base, a hollow ter-' Prior to permittinginsulating fluid to flow between the cable core and the interior orchamber 10 of the insulator the parts are carefully evacuated and filledwith degasified oil. In this respect the prior practice may be followedand therefore needs no description. v

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,-

, 1. An electric terminal comprising a metal base and cap, a chamberedinsulator located between the two and sealed at its ends thereby, ahollow conductor entering the insulator minal member carried by theconductor having a screw threaded portion and a port, a

hollow terminal member carried by the cap,

a flexible current carrying connector between the members, a valve seaton the first member through which and the port fluid flows between theconductor and the chamber, a screw threaded valve engaging the threadson the first mentioned member and cooperating with the seat to controlthe flow o fluid, a divided actuator for the valve having one partextending through the hollow member carried by the cap to the outsidethereof, means permitting relative axial movements of the parts of theactuator and preventing relative rotation of said parts, and a body of,fluid insulation filling the chamber and conductor.

2. An electric terminal comprising a metal base and cap, a chamberedinsulator located between the two and sealed at its ends thereby, ahollow conductor entering the insulator and supported by the base, ahollow terminal member carried by the conductor, a hollow terminalmember carried by the cap, a flexible current carrying connector betweenthe members, a valve seat and port in the first member through whichfluid fiows between the conductor and the chamber, a screw threadedvalve, a guide tube having screw threads to receive the valve carried bythe terminal member on the conductor and extending into the hollowmember an actuator for the valve extending through the guide tube andcomprising 'a rod and longitudinally slotted tube, a pin mounted in therod and traveling in the slot inthe tube, a screw for closing the outerend of the hollow member and to which the rod is secured, and a body ofinsulation filling the chamber and conductor.

3. In combination, an insulated, fluid filled conductor, tubular meansconnected to and forming a continuation of the conductor, a valvemovable within the means, said means and valve having cooperating screwthreads, a seat for the valve in said means,

a screw plugfor closing one end of the means, and an actuator for thevalve comprising two principal parts arranged in telescope relation, oneof the parts being permanently attached to the valve and the other tothe screw plug, and a pin carried by one of the parts and engaging theother to permit of relative longitudinal movement and prevent relativerotary movement.

4. An electric terminal comprising a metal base and cap, a chamberedinsulator situated between the base and cap and sealed at its endsthereby, a hollow core conductor secured to the base and extending intothe chamber of the insulator, a hollow terminal member secured to theconductor and forming a continuation thereof, said member having a valveseat and a port through which communication is established between thesaid chamber and the core of the conductor, a screw threaded valvelocated within the member and cooperating with the seat to control theport, a second terminal member carried by the cap and projectingoutwardly through it from said chamber, a yielding connection conveyingcurrent between the members, an'actuator for the valve accessible at theouter end of the second terminal, a slip connection between the valveand actuator permitting relative axial movements and preventing relativerotary movements, and a body of insulation filling the core of theconductor and the chamber of the insulator, said fluid being free toflow from one to the other when the valve is open.

5. An electric terminal comprising a metal base and cap, a chamberedinsulator situated between the base and the cap and sealed at its endsthereby, a hollow core conductor secured to the base and extending intothe chamber of the insulator, a hollow terminal member secured to theconductor and forming a continuation thereof, said member hav ing avalve seat and a lateral port, a guide tube carried by the member andscrew threaded for a short distance near its lower end, a valve threadedfor engagement with the threads on the tube and cooperating with theseat to control the passage of fluid through the port, a hollow terminalmember carried by the cap into which the guide tube extends, a currentcarrying flexible connection between the members, a divided actuator forthe valve having a part extending through the terminal member carried bythe cap to the outside thereof, said actuator having a means for closingthe outer end of the member and a slip connection between the partsthereof, and a body of fluid filling the conductor and the chamber ofthe insulator.

